Since a high-speed tool steel has an excellent wear resistance, the material has been used as a material for a cutting tool, such as end mill, drill, tap or milling cutter, and a cutoff tool such as band saw. Also, the high speed tool steel material is used for a material of some plastic-working molds, such as for press or forging (see Patent Literatures 1-3).
Typically, the high speed tool steel material is produced as follows: a steel ingot is cast from a molten steel having adjusted to have a predetermined composition (a casting step) and then the ingot as a starting material is subjected to various hot workings and heat treatments to produce a steel material having a predetermined dimension. In the above hot workings, the ingot is first hot-worked and bloomed into intermediate materials in a form of a slab, a bloom, a billet, a sheet bar etc. (blooming step). Then, the intermediate material is further hot-worked to finish it in a steel material having a shape corresponding to a product (finishing step). When the product produced from the steel material is end mill, drill, tap etc., the steel material is made to have a rod shape having a diameter or a side of its cross-section being about 5-50 mm for example. When the product is band saw etc., the steel material is made to have a wire shape having a diameter or a side of its cross-section being about 1-5 mm for example.
The high speed tool steel material is typically provided to a manufacturer of the product, such as cutting tool, in an annealed state having low hardness. The material provided to the manufacturer is machined in a shape of the product, and then is adjust to have predetermined use hardness through quenching and tempering. Usually, the material having been adjusted to have the use hardness is subjected to finishing machining. In a case of a band saw, the wire-shaped material is welded to a base material, and then is subjected to machining (sharpening process) and quenching and tempering.